Merge pull request #148 from pusher/proxy-session-store

Proxy session store
2019-05-20 12:55:39 +02:00 · 2019-05-20 12:55:39 +02:00 · 10e240c8bf
commit 10e240c8bf
parent 17e97ab884 d40a61613e
15 changed files with 226 additions and 275 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -10,6 +10,7 @@

 ## Changes since v3.2.0

+- [#148](https://github.com/pusher/outh2_proxy/pull/148) Implement SessionStore interface within proxy (@JoelSpeed)
 - [#147](https://github.com/pusher/outh2_proxy/pull/147) Add SessionStore interfaces and initial implementation (@JoelSpeed)
  - Allows for multiple different session storage implementations including client and server side
  - Adds tests suite for interface to ensure consistency across implementations
--- a/oauthproxy.go
+++ b/oauthproxy.go
@ -16,7 +16,7 @@ import (
 	"github.com/mbland/hmacauth"
 	"github.com/pusher/oauth2_proxy/cookie"
 	"github.com/pusher/oauth2_proxy/logger"
-	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
+	sessionsapi "github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/pusher/oauth2_proxy/providers"
 	"github.com/yhat/wsutil"
 )
@ -29,10 +29,6 @@ const (
 	httpScheme  = "http"
 	httpsScheme = "https"

-	// Cookies are limited to 4kb including the length of the cookie name,
-	// the cookie name can be up to 256 bytes
-	maxCookieLength = 3840
-
 	applicationJSON = "application/json"
 )

@ -75,6 +71,7 @@ type OAuthProxy struct {
 	redirectURL         *url.URL // the url to receive requests at
 	whitelistDomains    []string
 	provider            providers.Provider
+	sessionStore        sessionsapi.SessionStore
 	ProxyPrefix         string
 	SignInMessage       string
 	HtpasswdFile        *HtpasswdFile
@ -88,7 +85,6 @@ type OAuthProxy struct {
 	PassAccessToken     bool
 	SetAuthorization    bool
 	PassAuthorization   bool
-	CookieCipher        *cookie.Cipher
 	skipAuthRegex       []string
 	skipAuthPreflight   bool
 	compiledRegex       []*regexp.Regexp
@ -218,15 +214,6 @@ func NewOAuthProxy(opts *Options, validator func(string) bool) *OAuthProxy {

 	logger.Printf("Cookie settings: name:%s secure(https):%v httponly:%v expiry:%s domain:%s path:%s refresh:%s", opts.CookieName, opts.CookieSecure, opts.CookieHTTPOnly, opts.CookieExpire, opts.CookieDomain, opts.CookiePath, refresh)

-	var cipher *cookie.Cipher
-	if opts.PassAccessToken || opts.SetAuthorization || opts.PassAuthorization || (opts.CookieRefresh != time.Duration(0)) {
-		var err error
-		cipher, err = cookie.NewCipher(secretBytes(opts.CookieSecret))
-		if err != nil {
-			logger.Fatal("cookie-secret error: ", err)
-		}
-	}
-
 	return &OAuthProxy{
 		CookieName:     opts.CookieName,
 		CSRFCookieName: fmt.Sprintf("%v_%v", opts.CookieName, "csrf"),
@ -249,6 +236,7 @@ func NewOAuthProxy(opts *Options, validator func(string) bool) *OAuthProxy {

 		ProxyPrefix:        opts.ProxyPrefix,
 		provider:           opts.provider,
+		sessionStore:       opts.sessionStore,
 		serveMux:           serveMux,
 		redirectURL:        redirectURL,
 		whitelistDomains:   opts.WhitelistDomains,
@ -263,7 +251,6 @@ func NewOAuthProxy(opts *Options, validator func(string) bool) *OAuthProxy {
 		SetAuthorization:   opts.SetAuthorization,
 		PassAuthorization:  opts.PassAuthorization,
 		SkipProviderButton: opts.SkipProviderButton,
-		CookieCipher:       cipher,
 		templates:          loadTemplates(opts.CustomTemplatesDir),
 		Footer:             opts.Footer,
 	}
@ -293,7 +280,7 @@ func (p *OAuthProxy) displayCustomLoginForm() bool {
 	return p.HtpasswdFile != nil && p.DisplayHtpasswdForm
 }

-func (p *OAuthProxy) redeemCode(host, code string) (s *sessions.SessionState, err error) {
+func (p *OAuthProxy) redeemCode(host, code string) (s *sessionsapi.SessionState, err error) {
 	if code == "" {
 		return nil, errors.New("missing code")
 	}
@ -316,104 +303,6 @@ func (p *OAuthProxy) redeemCode(host, code string) (s *sessions.SessionState, er
 	return
 }

-// MakeSessionCookie creates an http.Cookie containing the authenticated user's
-// authentication details
-func (p *OAuthProxy) MakeSessionCookie(req *http.Request, value string, expiration time.Duration, now time.Time) []*http.Cookie {
-	if value != "" {
-		value = cookie.SignedValue(p.CookieSeed, p.CookieName, value, now)
-	}
-	c := p.makeCookie(req, p.CookieName, value, expiration, now)
-	if len(c.Value) > 4096-len(p.CookieName) {
-		return splitCookie(c)
-	}
-	return []*http.Cookie{c}
-}
-
-func copyCookie(c *http.Cookie) *http.Cookie {
-	return &http.Cookie{
-		Name:       c.Name,
-		Value:      c.Value,
-		Path:       c.Path,
-		Domain:     c.Domain,
-		Expires:    c.Expires,
-		RawExpires: c.RawExpires,
-		MaxAge:     c.MaxAge,
-		Secure:     c.Secure,
-		HttpOnly:   c.HttpOnly,
-		Raw:        c.Raw,
-		Unparsed:   c.Unparsed,
-	}
-}
-
-// splitCookie reads the full cookie generated to store the session and splits
-// it into a slice of cookies which fit within the 4kb cookie limit indexing
-// the cookies from 0
-func splitCookie(c *http.Cookie) []*http.Cookie {
-	if len(c.Value) < maxCookieLength {
-		return []*http.Cookie{c}
-	}
-	cookies := []*http.Cookie{}
-	valueBytes := []byte(c.Value)
-	count := 0
-	for len(valueBytes) > 0 {
-		new := copyCookie(c)
-		new.Name = fmt.Sprintf("%s_%d", c.Name, count)
-		count++
-		if len(valueBytes) < maxCookieLength {
-			new.Value = string(valueBytes)
-			valueBytes = []byte{}
-		} else {
-			newValue := valueBytes[:maxCookieLength]
-			valueBytes = valueBytes[maxCookieLength:]
-			new.Value = string(newValue)
-		}
-		cookies = append(cookies, new)
-	}
-	return cookies
-}
-
-// joinCookies takes a slice of cookies from the request and reconstructs the
-// full session cookie
-func joinCookies(cookies []*http.Cookie) (*http.Cookie, error) {
-	if len(cookies) == 0 {
-		return nil, fmt.Errorf("list of cookies must be > 0")
-	}
-	if len(cookies) == 1 {
-		return cookies[0], nil
-	}
-	c := copyCookie(cookies[0])
-	for i := 1; i < len(cookies); i++ {
-		c.Value += cookies[i].Value
-	}
-	c.Name = strings.TrimRight(c.Name, "_0")
-	return c, nil
-}
-
-// loadCookie retreieves the sessions state cookie from the http request.
-// If a single cookie is present this will be returned, otherwise it attempts
-// to reconstruct a cookie split up by splitCookie
-func loadCookie(req *http.Request, cookieName string) (*http.Cookie, error) {
-	c, err := req.Cookie(cookieName)
-	if err == nil {
-		return c, nil
-	}
-	cookies := []*http.Cookie{}
-	err = nil
-	count := 0
-	for err == nil {
-		var c *http.Cookie
-		c, err = req.Cookie(fmt.Sprintf("%s_%d", cookieName, count))
-		if err == nil {
-			cookies = append(cookies, c)
-			count++
-		}
-	}
-	if len(cookies) == 0 {
-		return nil, fmt.Errorf("Could not find cookie %s", cookieName)
-	}
-	return joinCookies(cookies)
-}
-
 // MakeCSRFCookie creates a cookie for CSRF
 func (p *OAuthProxy) MakeCSRFCookie(req *http.Request, value string, expiration time.Duration, now time.Time) *http.Cookie {
 	return p.makeCookie(req, p.CSRFCookieName, value, expiration, now)
@ -454,66 +343,18 @@ func (p *OAuthProxy) SetCSRFCookie(rw http.ResponseWriter, req *http.Request, va

 // ClearSessionCookie creates a cookie to unset the user's authentication cookie
 // stored in the user's session
-func (p *OAuthProxy) ClearSessionCookie(rw http.ResponseWriter, req *http.Request) {
-	var cookies []*http.Cookie
-
-	// matches CookieName, CookieName_<number>
-	var cookieNameRegex = regexp.MustCompile(fmt.Sprintf("^%s(_\\d+)?$", p.CookieName))
-
-	for _, c := range req.Cookies() {
-		if cookieNameRegex.MatchString(c.Name) {
-			clearCookie := p.makeCookie(req, c.Name, "", time.Hour*-1, time.Now())
-
-			http.SetCookie(rw, clearCookie)
-			cookies = append(cookies, clearCookie)
-		}
-	}
-
-	// ugly hack because default domain changed
-	if p.CookieDomain == "" && len(cookies) > 0 {
-		clr2 := *cookies[0]
-		clr2.Domain = req.Host
-		http.SetCookie(rw, &clr2)
-	}
-}
-
-// SetSessionCookie adds the user's session cookie to the response
-func (p *OAuthProxy) SetSessionCookie(rw http.ResponseWriter, req *http.Request, val string) {
-	for _, c := range p.MakeSessionCookie(req, val, p.CookieExpire, time.Now()) {
-		http.SetCookie(rw, c)
-	}
+func (p *OAuthProxy) ClearSessionCookie(rw http.ResponseWriter, req *http.Request) error {
+	return p.sessionStore.Clear(rw, req)
 }

 // LoadCookiedSession reads the user's authentication details from the request
-func (p *OAuthProxy) LoadCookiedSession(req *http.Request) (*sessions.SessionState, time.Duration, error) {
-	var age time.Duration
-	c, err := loadCookie(req, p.CookieName)
-	if err != nil {
-		// always http.ErrNoCookie
-		return nil, age, fmt.Errorf("Cookie %q not present", p.CookieName)
-	}
-	val, timestamp, ok := cookie.Validate(c, p.CookieSeed, p.CookieExpire)
-	if !ok {
-		return nil, age, errors.New("Cookie Signature not valid")
-	}
-
-	session, err := p.provider.SessionFromCookie(val, p.CookieCipher)
-	if err != nil {
-		return nil, age, err
-	}
-
-	age = time.Now().Truncate(time.Second).Sub(timestamp)
-	return session, age, nil
+func (p *OAuthProxy) LoadCookiedSession(req *http.Request) (*sessionsapi.SessionState, error) {
+	return p.sessionStore.Load(req)
 }

 // SaveSession creates a new session cookie value and sets this on the response
-func (p *OAuthProxy) SaveSession(rw http.ResponseWriter, req *http.Request, s *sessions.SessionState) error {
-	value, err := p.provider.CookieForSession(s, p.CookieCipher)
-	if err != nil {
-		return err
-	}
-	p.SetSessionCookie(rw, req, value)
-	return nil
+func (p *OAuthProxy) SaveSession(rw http.ResponseWriter, req *http.Request, s *sessionsapi.SessionState) error {
+	return p.sessionStore.Save(rw, req, s)
 }

 // RobotsTxt disallows scraping pages from the OAuthProxy
@ -694,7 +535,7 @@ func (p *OAuthProxy) SignIn(rw http.ResponseWriter, req *http.Request) {

 	user, ok := p.ManualSignIn(rw, req)
 	if ok {
-		session := &sessions.SessionState{User: user}
+		session := &sessionsapi.SessionState{User: user}
 		p.SaveSession(rw, req, session)
 		http.Redirect(rw, req, redirect, 302)
 	} else {
@ -833,12 +674,12 @@ func (p *OAuthProxy) Authenticate(rw http.ResponseWriter, req *http.Request) int
 	var saveSession, clearSession, revalidated bool
 	remoteAddr := getRemoteAddr(req)

-	session, sessionAge, err := p.LoadCookiedSession(req)
+	session, err := p.LoadCookiedSession(req)
 	if err != nil {
 		logger.Printf("Error loading cookied session: %s", err)
 	}
-	if session != nil && sessionAge > p.CookieRefresh && p.CookieRefresh != time.Duration(0) {
-		logger.Printf("Refreshing %s old session cookie for %s (refresh after %s)", sessionAge, session, p.CookieRefresh)
+	if session != nil && session.Age() > p.CookieRefresh && p.CookieRefresh != time.Duration(0) {
+		logger.Printf("Refreshing %s old session cookie for %s (refresh after %s)", session.Age(), session, p.CookieRefresh)
 		saveSession = true
 	}

@ -945,7 +786,7 @@ func (p *OAuthProxy) Authenticate(rw http.ResponseWriter, req *http.Request) int

 // CheckBasicAuth checks the requests Authorization header for basic auth
 // credentials and authenticates these against the proxies HtpasswdFile
-func (p *OAuthProxy) CheckBasicAuth(req *http.Request) (*sessions.SessionState, error) {
+func (p *OAuthProxy) CheckBasicAuth(req *http.Request) (*sessionsapi.SessionState, error) {
 	if p.HtpasswdFile == nil {
 		return nil, nil
 	}
@ -967,7 +808,7 @@ func (p *OAuthProxy) CheckBasicAuth(req *http.Request) (*sessions.SessionState,
 	}
 	if p.HtpasswdFile.Validate(pair[0], pair[1]) {
 		logger.PrintAuthf(pair[0], req, logger.AuthSuccess, "Authenticated via basic auth and HTpasswd File")
-		return &sessions.SessionState{User: pair[0]}, nil
+		return &sessionsapi.SessionState{User: pair[0]}, nil
 	}
 	logger.PrintAuthf(pair[0], req, logger.AuthFailure, "Invalid authentication via basic auth: not in Htpasswd File")
 	return nil, nil
--- a/oauthproxy_test.go
+++ b/oauthproxy_test.go
@ -17,6 +17,7 @@ import (
 	"github.com/mbland/hmacauth"
 	"github.com/pusher/oauth2_proxy/logger"
 	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
+	"github.com/pusher/oauth2_proxy/pkg/sessions/cookie"
 	"github.com/pusher/oauth2_proxy/providers"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@ -600,10 +601,15 @@ type ProcessCookieTestOpts struct {
 	providerValidateCookieResponse bool
 }

-func NewProcessCookieTest(opts ProcessCookieTestOpts) *ProcessCookieTest {
+type OptionsModifier func(*Options)
+
+func NewProcessCookieTest(opts ProcessCookieTestOpts, modifiers ...OptionsModifier) *ProcessCookieTest {
 	var pcTest ProcessCookieTest

 	pcTest.opts = NewOptions()
+	for _, modifier := range modifiers {
+		modifier(pcTest.opts)
+	}
 	pcTest.opts.ClientID = "bazquux"
 	pcTest.opts.ClientSecret = "xyzzyplugh"
 	pcTest.opts.CookieSecret = "0123456789abcdefabcd"
@ -634,32 +640,34 @@ func NewProcessCookieTestWithDefaults() *ProcessCookieTest {
 	})
 }

-func (p *ProcessCookieTest) MakeCookie(value string, ref time.Time) []*http.Cookie {
-	return p.proxy.MakeSessionCookie(p.req, value, p.opts.CookieExpire, ref)
+func NewProcessCookieTestWithOptionsModifiers(modifiers ...OptionsModifier) *ProcessCookieTest {
+	return NewProcessCookieTest(ProcessCookieTestOpts{
+		providerValidateCookieResponse: true,
+	}, modifiers...)
 }

-func (p *ProcessCookieTest) SaveSession(s *sessions.SessionState, ref time.Time) error {
-	value, err := p.proxy.provider.CookieForSession(s, p.proxy.CookieCipher)
+func (p *ProcessCookieTest) SaveSession(s *sessions.SessionState) error {
+	err := p.proxy.SaveSession(p.rw, p.req, s)
 	if err != nil {
 		return err
 	}
-	for _, c := range p.proxy.MakeSessionCookie(p.req, value, p.proxy.CookieExpire, ref) {
-		p.req.AddCookie(c)
+	for _, cookie := range p.rw.Result().Cookies() {
+		p.req.AddCookie(cookie)
 	}
 	return nil
 }

-func (p *ProcessCookieTest) LoadCookiedSession() (*sessions.SessionState, time.Duration, error) {
+func (p *ProcessCookieTest) LoadCookiedSession() (*sessions.SessionState, error) {
 	return p.proxy.LoadCookiedSession(p.req)
 }

 func TestLoadCookiedSession(t *testing.T) {
 	pcTest := NewProcessCookieTestWithDefaults()

-	startSession := &sessions.SessionState{Email: "john.doe@example.com", AccessToken: "my_access_token"}
-	pcTest.SaveSession(startSession, time.Now())
+	startSession := &sessions.SessionState{Email: "john.doe@example.com", AccessToken: "my_access_token", CreatedAt: time.Now()}
+	pcTest.SaveSession(startSession)

-	session, _, err := pcTest.LoadCookiedSession()
+	session, err := pcTest.LoadCookiedSession()
 	assert.Equal(t, nil, err)
 	assert.Equal(t, startSession.Email, session.Email)
 	assert.Equal(t, "john.doe@example.com", session.User)
@ -669,7 +677,7 @@ func TestLoadCookiedSession(t *testing.T) {
 func TestProcessCookieNoCookieError(t *testing.T) {
 	pcTest := NewProcessCookieTestWithDefaults()

-	session, _, err := pcTest.LoadCookiedSession()
+	session, err := pcTest.LoadCookiedSession()
 	assert.Equal(t, "Cookie \"_oauth2_proxy\" not present", err.Error())
 	if session != nil {
 		t.Errorf("expected nil session. got %#v", session)
@ -677,29 +685,31 @@ func TestProcessCookieNoCookieError(t *testing.T) {
 }

 func TestProcessCookieRefreshNotSet(t *testing.T) {
-	pcTest := NewProcessCookieTestWithDefaults()
-	pcTest.proxy.CookieExpire = time.Duration(23) * time.Hour
+	pcTest := NewProcessCookieTestWithOptionsModifiers(func(opts *Options) {
+		opts.CookieExpire = time.Duration(23) * time.Hour
+	})
 	reference := time.Now().Add(time.Duration(-2) * time.Hour)

-	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
-	pcTest.SaveSession(startSession, reference)
+	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token", CreatedAt: reference}
+	pcTest.SaveSession(startSession)

-	session, age, err := pcTest.LoadCookiedSession()
+	session, err := pcTest.LoadCookiedSession()
 	assert.Equal(t, nil, err)
-	if age < time.Duration(-2)*time.Hour {
-		t.Errorf("cookie too young %v", age)
+	if session.Age() < time.Duration(-2)*time.Hour {
+		t.Errorf("cookie too young %v", session.Age())
 	}
 	assert.Equal(t, startSession.Email, session.Email)
 }

 func TestProcessCookieFailIfCookieExpired(t *testing.T) {
-	pcTest := NewProcessCookieTestWithDefaults()
-	pcTest.proxy.CookieExpire = time.Duration(24) * time.Hour
+	pcTest := NewProcessCookieTestWithOptionsModifiers(func(opts *Options) {
+		opts.CookieExpire = time.Duration(24) * time.Hour
+	})
 	reference := time.Now().Add(time.Duration(25) * time.Hour * -1)
-	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
-	pcTest.SaveSession(startSession, reference)
+	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token", CreatedAt: reference}
+	pcTest.SaveSession(startSession)

-	session, _, err := pcTest.LoadCookiedSession()
+	session, err := pcTest.LoadCookiedSession()
 	assert.NotEqual(t, nil, err)
 	if session != nil {
 		t.Errorf("expected nil session %#v", session)
@ -707,22 +717,23 @@ func TestProcessCookieFailIfCookieExpired(t *testing.T) {
 }

 func TestProcessCookieFailIfRefreshSetAndCookieExpired(t *testing.T) {
-	pcTest := NewProcessCookieTestWithDefaults()
-	pcTest.proxy.CookieExpire = time.Duration(24) * time.Hour
+	pcTest := NewProcessCookieTestWithOptionsModifiers(func(opts *Options) {
+		opts.CookieExpire = time.Duration(24) * time.Hour
+	})
 	reference := time.Now().Add(time.Duration(25) * time.Hour * -1)
-	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
-	pcTest.SaveSession(startSession, reference)
+	startSession := &sessions.SessionState{Email: "michael.bland@gsa.gov", AccessToken: "my_access_token", CreatedAt: reference}
+	pcTest.SaveSession(startSession)

 	pcTest.proxy.CookieRefresh = time.Hour
-	session, _, err := pcTest.LoadCookiedSession()
+	session, err := pcTest.LoadCookiedSession()
 	assert.NotEqual(t, nil, err)
 	if session != nil {
 		t.Errorf("expected nil session %#v", session)
 	}
 }

-func NewAuthOnlyEndpointTest() *ProcessCookieTest {
-	pcTest := NewProcessCookieTestWithDefaults()
+func NewAuthOnlyEndpointTest(modifiers ...OptionsModifier) *ProcessCookieTest {
+	pcTest := NewProcessCookieTestWithOptionsModifiers(modifiers...)
 	pcTest.req, _ = http.NewRequest("GET",
 		pcTest.opts.ProxyPrefix+"/auth", nil)
 	return pcTest
@ -731,8 +742,8 @@ func NewAuthOnlyEndpointTest() *ProcessCookieTest {
 func TestAuthOnlyEndpointAccepted(t *testing.T) {
 	test := NewAuthOnlyEndpointTest()
 	startSession := &sessions.SessionState{
-		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
-	test.SaveSession(startSession, time.Now())
+		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token", CreatedAt: time.Now()}
+	test.SaveSession(startSession)

 	test.proxy.ServeHTTP(test.rw, test.req)
 	assert.Equal(t, http.StatusAccepted, test.rw.Code)
@ -750,12 +761,13 @@ func TestAuthOnlyEndpointUnauthorizedOnNoCookieSetError(t *testing.T) {
 }

 func TestAuthOnlyEndpointUnauthorizedOnExpiration(t *testing.T) {
-	test := NewAuthOnlyEndpointTest()
-	test.proxy.CookieExpire = time.Duration(24) * time.Hour
+	test := NewAuthOnlyEndpointTest(func(opts *Options) {
+		opts.CookieExpire = time.Duration(24) * time.Hour
+	})
 	reference := time.Now().Add(time.Duration(25) * time.Hour * -1)
 	startSession := &sessions.SessionState{
-		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
-	test.SaveSession(startSession, reference)
+		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token", CreatedAt: reference}
+	test.SaveSession(startSession)

 	test.proxy.ServeHTTP(test.rw, test.req)
 	assert.Equal(t, http.StatusUnauthorized, test.rw.Code)
@ -766,8 +778,8 @@ func TestAuthOnlyEndpointUnauthorizedOnExpiration(t *testing.T) {
 func TestAuthOnlyEndpointUnauthorizedOnEmailValidationFailure(t *testing.T) {
 	test := NewAuthOnlyEndpointTest()
 	startSession := &sessions.SessionState{
-		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token"}
-	test.SaveSession(startSession, time.Now())
+		Email: "michael.bland@gsa.gov", AccessToken: "my_access_token", CreatedAt: time.Now()}
+	test.SaveSession(startSession)
 	test.validateUser = false

 	test.proxy.ServeHTTP(test.rw, test.req)
@ -797,8 +809,8 @@ func TestAuthOnlyEndpointSetXAuthRequestHeaders(t *testing.T) {
 		pcTest.opts.ProxyPrefix+"/auth", nil)

 	startSession := &sessions.SessionState{
-		User: "oauth_user", Email: "oauth_user@example.com", AccessToken: "oauth_token"}
-	pcTest.SaveSession(startSession, time.Now())
+		User: "oauth_user", Email: "oauth_user@example.com", AccessToken: "oauth_token", CreatedAt: time.Now()}
+	pcTest.SaveSession(startSession)

 	pcTest.proxy.ServeHTTP(pcTest.rw, pcTest.req)
 	assert.Equal(t, http.StatusAccepted, pcTest.rw.Code)
@ -930,11 +942,11 @@ func (st *SignatureTest) MakeRequestWithExpectedKey(method, body, key string) {

 	state := &sessions.SessionState{
 		Email: "mbland@acm.org", AccessToken: "my_access_token"}
-	value, err := proxy.provider.CookieForSession(state, proxy.CookieCipher)
+	err = proxy.SaveSession(st.rw, req, state)
 	if err != nil {
 		panic(err)
 	}
-	for _, c := range proxy.MakeSessionCookie(req, value, proxy.CookieExpire, time.Now()) {
+	for _, c := range st.rw.Result().Cookies() {
 		req.AddCookie(c)
 	}
 	// This is used by the upstream to validate the signature.
@ -1068,7 +1080,12 @@ func TestAjaxForbiddendRequest(t *testing.T) {
 }

 func TestClearSplitCookie(t *testing.T) {
-	p := OAuthProxy{CookieName: "oauth2", CookieDomain: "abc"}
+	opts := NewOptions()
+	opts.CookieName = "oauth2"
+	opts.CookieDomain = "abc"
+	store, err := cookie.NewCookieSessionStore(&opts.SessionOptions, &opts.CookieOptions)
+	assert.Equal(t, err, nil)
+	p := OAuthProxy{CookieName: opts.CookieName, CookieDomain: opts.CookieDomain, sessionStore: store}
 	var rw = httptest.NewRecorder()
 	req := httptest.NewRequest("get", "/", nil)

@ -1092,7 +1109,12 @@ func TestClearSplitCookie(t *testing.T) {
 }

 func TestClearSingleCookie(t *testing.T) {
-	p := OAuthProxy{CookieName: "oauth2", CookieDomain: "abc"}
+	opts := NewOptions()
+	opts.CookieName = "oauth2"
+	opts.CookieDomain = "abc"
+	store, err := cookie.NewCookieSessionStore(&opts.SessionOptions, &opts.CookieOptions)
+	assert.Equal(t, err, nil)
+	p := OAuthProxy{CookieName: opts.CookieName, CookieDomain: opts.CookieDomain, sessionStore: store}
 	var rw = httptest.NewRecorder()
 	req := httptest.NewRequest("get", "/", nil)

--- a/options.go
+++ b/options.go
@ -17,8 +17,11 @@ import (
 	oidc "github.com/coreos/go-oidc"
 	"github.com/dgrijalva/jwt-go"
 	"github.com/mbland/hmacauth"
+	"github.com/pusher/oauth2_proxy/cookie"
 	"github.com/pusher/oauth2_proxy/logger"
 	"github.com/pusher/oauth2_proxy/pkg/apis/options"
+	sessionsapi "github.com/pusher/oauth2_proxy/pkg/apis/sessions"
+	"github.com/pusher/oauth2_proxy/pkg/sessions"
 	"github.com/pusher/oauth2_proxy/providers"
 	"gopkg.in/natefinch/lumberjack.v2"
 )
@ -111,6 +114,7 @@ type Options struct {
 	proxyURLs     []*url.URL
 	CompiledRegex []*regexp.Regexp
 	provider      providers.Provider
+	sessionStore  sessionsapi.SessionStore
 	signatureData *SignatureData
 	oidcVerifier  *oidc.IDTokenVerifier
 }
@ -136,6 +140,9 @@ func NewOptions() *Options {
 			CookieExpire:   time.Duration(168) * time.Hour,
 			CookieRefresh:  time.Duration(0),
 		},
+		SessionOptions: options.SessionOptions{
+			Type: "cookie",
+		},
 		SetXAuthRequest:       false,
 		SkipAuthPreflight:     false,
 		PassBasicAuth:         true,
@ -261,7 +268,8 @@ func (o *Options) Validate() error {
 	}
 	msgs = parseProviderInfo(o, msgs)

-	if o.PassAccessToken || (o.CookieRefresh != time.Duration(0)) {
+	var cipher *cookie.Cipher
+	if o.PassAccessToken || o.SetAuthorization || o.PassAuthorization || (o.CookieRefresh != time.Duration(0)) {
 		validCookieSecretSize := false
 		for _, i := range []int{16, 24, 32} {
 			if len(secretBytes(o.CookieSecret)) == i {
@ -283,8 +291,22 @@ func (o *Options) Validate() error {
 					"pass_access_token == true or "+
 					"cookie_refresh != 0, but is %d bytes.%s",
 				len(secretBytes(o.CookieSecret)), suffix))
+		} else {
+			var err error
+			cipher, err = cookie.NewCipher(secretBytes(o.CookieSecret))
+			if err != nil {
+				msgs = append(msgs, fmt.Sprintf("cookie-secret error: %v", err))
 			}
 		}
+	}
+
+	o.SessionOptions.Cipher = cipher
+	sessionStore, err := sessions.NewSessionStore(&o.SessionOptions, &o.CookieOptions)
+	if err != nil {
+		msgs = append(msgs, fmt.Sprintf("error initialising session storage: %v", err))
+	} else {
+		o.sessionStore = sessionStore
+	}

 	if o.CookieRefresh >= o.CookieExpire {
 		msgs = append(msgs, fmt.Sprintf(
--- a/pkg/apis/options/sessions.go
+++ b/pkg/apis/options/sessions.go
@ -1,8 +1,13 @@
 package options

+import (
+	"github.com/pusher/oauth2_proxy/cookie"
+)
+
 // SessionOptions contains configuration options for the SessionStore providers.
 type SessionOptions struct {
 	Type   string `flag:"session-store-type" cfg:"session_store_type" env:"OAUTH2_PROXY_SESSION_STORE_TYPE"`
+	Cipher *cookie.Cipher
 	CookieStoreOptions
 }

--- a/pkg/apis/sessions/session_state.go
+++ b/pkg/apis/sessions/session_state.go
@ -14,6 +14,7 @@ import (
 type SessionState struct {
 	AccessToken  string    `json:",omitempty"`
 	IDToken      string    `json:",omitempty"`
+	CreatedAt    time.Time `json:"-"`
 	ExpiresOn    time.Time `json:"-"`
 	RefreshToken string    `json:",omitempty"`
 	Email        string    `json:",omitempty"`
@ -23,6 +24,7 @@ type SessionState struct {
 // SessionStateJSON is used to encode SessionState into JSON without exposing time.Time zero value
 type SessionStateJSON struct {
 	*SessionState
+	CreatedAt *time.Time `json:",omitempty"`
 	ExpiresOn *time.Time `json:",omitempty"`
 }

@ -34,6 +36,14 @@ func (s *SessionState) IsExpired() bool {
 	return false
 }

+// Age returns the age of a session
+func (s *SessionState) Age() time.Duration {
+	if !s.CreatedAt.IsZero() {
+		return time.Now().Truncate(time.Second).Sub(s.CreatedAt)
+	}
+	return 0
+}
+
 // String constructs a summary of the session state
 func (s *SessionState) String() string {
 	o := fmt.Sprintf("Session{email:%s user:%s", s.Email, s.User)
@ -43,6 +53,9 @@ func (s *SessionState) String() string {
 	if s.IDToken != "" {
 		o += " id_token:true"
 	}
+	if !s.CreatedAt.IsZero() {
+		o += fmt.Sprintf(" created:%s", s.CreatedAt)
+	}
 	if !s.ExpiresOn.IsZero() {
 		o += fmt.Sprintf(" expires:%s", s.ExpiresOn)
 	}
@ -95,6 +108,9 @@ func (s *SessionState) EncodeSessionState(c *cookie.Cipher) (string, error) {
 	}
 	// Embed SessionState and ExpiresOn pointer into SessionStateJSON
 	ssj := &SessionStateJSON{SessionState: &ss}
+	if !ss.CreatedAt.IsZero() {
+		ssj.CreatedAt = &ss.CreatedAt
+	}
 	if !ss.ExpiresOn.IsZero() {
 		ssj.ExpiresOn = &ss.ExpiresOn
 	}
@ -165,8 +181,11 @@ func DecodeSessionState(v string, c *cookie.Cipher) (*SessionState, error) {
 	var ss *SessionState
 	err := json.Unmarshal([]byte(v), &ssj)
 	if err == nil && ssj.SessionState != nil {
-		// Extract SessionState and ExpiresOn value from SessionStateJSON
+		// Extract SessionState and CreatedAt,ExpiresOn value from SessionStateJSON
 		ss = ssj.SessionState
+		if ssj.CreatedAt != nil {
+			ss.CreatedAt = *ssj.CreatedAt
+		}
 		if ssj.ExpiresOn != nil {
 			ss.ExpiresOn = *ssj.ExpiresOn
 		}
--- a/pkg/apis/sessions/session_state_test.go
+++ b/pkg/apis/sessions/session_state_test.go
@ -22,6 +22,7 @@ func TestSessionStateSerialization(t *testing.T) {
 		Email:        "user@domain.com",
 		AccessToken:  "token1234",
 		IDToken:      "rawtoken1234",
+		CreatedAt:    time.Now(),
 		ExpiresOn:    time.Now().Add(time.Duration(1) * time.Hour),
 		RefreshToken: "refresh4321",
 	}
@ -35,6 +36,7 @@ func TestSessionStateSerialization(t *testing.T) {
 	assert.Equal(t, s.Email, ss.Email)
 	assert.Equal(t, s.AccessToken, ss.AccessToken)
 	assert.Equal(t, s.IDToken, ss.IDToken)
+	assert.Equal(t, s.CreatedAt.Unix(), ss.CreatedAt.Unix())
 	assert.Equal(t, s.ExpiresOn.Unix(), ss.ExpiresOn.Unix())
 	assert.Equal(t, s.RefreshToken, ss.RefreshToken)

@ -44,6 +46,7 @@ func TestSessionStateSerialization(t *testing.T) {
 	assert.Equal(t, nil, err)
 	assert.NotEqual(t, "user@domain.com", ss.User)
 	assert.NotEqual(t, s.Email, ss.Email)
+	assert.Equal(t, s.CreatedAt.Unix(), ss.CreatedAt.Unix())
 	assert.Equal(t, s.ExpiresOn.Unix(), ss.ExpiresOn.Unix())
 	assert.NotEqual(t, s.AccessToken, ss.AccessToken)
 	assert.NotEqual(t, s.IDToken, ss.IDToken)
@ -59,6 +62,7 @@ func TestSessionStateSerializationWithUser(t *testing.T) {
 		User:         "just-user",
 		Email:        "user@domain.com",
 		AccessToken:  "token1234",
+		CreatedAt:    time.Now(),
 		ExpiresOn:    time.Now().Add(time.Duration(1) * time.Hour),
 		RefreshToken: "refresh4321",
 	}
@ -71,6 +75,7 @@ func TestSessionStateSerializationWithUser(t *testing.T) {
 	assert.Equal(t, s.User, ss.User)
 	assert.Equal(t, s.Email, ss.Email)
 	assert.Equal(t, s.AccessToken, ss.AccessToken)
+	assert.Equal(t, s.CreatedAt.Unix(), ss.CreatedAt.Unix())
 	assert.Equal(t, s.ExpiresOn.Unix(), ss.ExpiresOn.Unix())
 	assert.Equal(t, s.RefreshToken, ss.RefreshToken)

@ -80,6 +85,7 @@ func TestSessionStateSerializationWithUser(t *testing.T) {
 	assert.Equal(t, nil, err)
 	assert.NotEqual(t, s.User, ss.User)
 	assert.NotEqual(t, s.Email, ss.Email)
+	assert.Equal(t, s.CreatedAt.Unix(), ss.CreatedAt.Unix())
 	assert.Equal(t, s.ExpiresOn.Unix(), ss.ExpiresOn.Unix())
 	assert.NotEqual(t, s.AccessToken, ss.AccessToken)
 	assert.NotEqual(t, s.RefreshToken, ss.RefreshToken)
@ -89,6 +95,7 @@ func TestSessionStateSerializationNoCipher(t *testing.T) {
 	s := &sessions.SessionState{
 		Email:        "user@domain.com",
 		AccessToken:  "token1234",
+		CreatedAt:    time.Now(),
 		ExpiresOn:    time.Now().Add(time.Duration(1) * time.Hour),
 		RefreshToken: "refresh4321",
 	}
@ -109,6 +116,7 @@ func TestSessionStateSerializationNoCipherWithUser(t *testing.T) {
 		User:         "just-user",
 		Email:        "user@domain.com",
 		AccessToken:  "token1234",
+		CreatedAt:    time.Now(),
 		ExpiresOn:    time.Now().Add(time.Duration(1) * time.Hour),
 		RefreshToken: "refresh4321",
 	}
@ -147,6 +155,7 @@ type testCase struct {
 // Currently only tests without cipher here because we have no way to mock
 // the random generator used in EncodeSessionState.
 func TestEncodeSessionState(t *testing.T) {
+	c := time.Now()
 	e := time.Now().Add(time.Duration(1) * time.Hour)

 	testCases := []testCase{
@ -163,6 +172,7 @@ func TestEncodeSessionState(t *testing.T) {
 				User:         "just-user",
 				AccessToken:  "token1234",
 				IDToken:      "rawtoken1234",
+				CreatedAt:    c,
 				ExpiresOn:    e,
 				RefreshToken: "refresh4321",
 			},
@ -185,6 +195,9 @@ func TestEncodeSessionState(t *testing.T) {

 // TestDecodeSessionState testssessions.DecodeSessionState with the test vector
 func TestDecodeSessionState(t *testing.T) {
+	created := time.Now()
+	createdJSON, _ := created.MarshalJSON()
+	createdString := string(createdJSON)
 	e := time.Now().Add(time.Duration(1) * time.Hour)
 	eJSON, _ := e.MarshalJSON()
 	eString := string(eJSON)
@ -219,7 +232,7 @@ func TestDecodeSessionState(t *testing.T) {
 				Email: "user@domain.com",
 				User:  "just-user",
 			},
-			Encoded: fmt.Sprintf(`{"Email":"user@domain.com","User":"just-user","AccessToken":"I6s+ml+/MldBMgHIiC35BTKTh57skGX24w==","IDToken":"xojNdyyjB1HgYWh6XMtXY/Ph5eCVxa1cNsklJw==","RefreshToken":"qEX0x6RmASxo4dhlBG6YuRs9Syn/e9sHu/+K","ExpiresOn":%s}`, eString),
+			Encoded: fmt.Sprintf(`{"Email":"user@domain.com","User":"just-user","AccessToken":"I6s+ml+/MldBMgHIiC35BTKTh57skGX24w==","IDToken":"xojNdyyjB1HgYWh6XMtXY/Ph5eCVxa1cNsklJw==","RefreshToken":"qEX0x6RmASxo4dhlBG6YuRs9Syn/e9sHu/+K","CreatedAt":%s,"ExpiresOn":%s}`, createdString, eString),
 		},
 		{
 			SessionState: sessions.SessionState{
@ -227,10 +240,11 @@ func TestDecodeSessionState(t *testing.T) {
 				User:         "just-user",
 				AccessToken:  "token1234",
 				IDToken:      "rawtoken1234",
+				CreatedAt:    created,
 				ExpiresOn:    e,
 				RefreshToken: "refresh4321",
 			},
-			Encoded: fmt.Sprintf(`{"Email":"FsKKYrTWZWrxSOAqA/fTNAUZS5QWCqOBjuAbBlbVOw==","User":"rT6JP3dxQhxUhkWrrd7yt6c1mDVyQCVVxw==","AccessToken":"I6s+ml+/MldBMgHIiC35BTKTh57skGX24w==","IDToken":"xojNdyyjB1HgYWh6XMtXY/Ph5eCVxa1cNsklJw==","RefreshToken":"qEX0x6RmASxo4dhlBG6YuRs9Syn/e9sHu/+K","ExpiresOn":%s}`, eString),
+			Encoded: fmt.Sprintf(`{"Email":"FsKKYrTWZWrxSOAqA/fTNAUZS5QWCqOBjuAbBlbVOw==","User":"rT6JP3dxQhxUhkWrrd7yt6c1mDVyQCVVxw==","AccessToken":"I6s+ml+/MldBMgHIiC35BTKTh57skGX24w==","IDToken":"xojNdyyjB1HgYWh6XMtXY/Ph5eCVxa1cNsklJw==","RefreshToken":"qEX0x6RmASxo4dhlBG6YuRs9Syn/e9sHu/+K","CreatedAt":%s,"ExpiresOn":%s}`, createdString, eString),
 			Cipher:  c,
 		},
 		{
@ -316,3 +330,14 @@ func TestDecodeSessionState(t *testing.T) {
 		}
 	}
 }
+
+func TestSessionStateAge(t *testing.T) {
+	ss := &sessions.SessionState{}
+
+	// Created at unset so should be 0
+	assert.Equal(t, time.Duration(0), ss.Age())
+
+	// Set CreatedAt to 1 hour ago
+	ss.CreatedAt = time.Now().Add(-1 * time.Hour)
+	assert.Equal(t, time.Hour, ss.Age().Round(time.Minute))
+}
--- a/pkg/cookies/cookies.go
+++ b/pkg/cookies/cookies.go
@ -7,6 +7,7 @@ import (
 	"time"

 	"github.com/pusher/oauth2_proxy/logger"
+	"github.com/pusher/oauth2_proxy/pkg/apis/options"
 )

 // MakeCookie constructs a cookie from the given parameters,
@ -32,3 +33,9 @@ func MakeCookie(req *http.Request, name string, value string, path string, domai
 		Expires:  now.Add(expiration),
 	}
 }
+
+// MakeCookieFromOptions constructs a cookie based on the givemn *options.CookieOptions,
+// value and creation time
+func MakeCookieFromOptions(req *http.Request, name string, value string, opts *options.CookieOptions, expiration time.Duration, now time.Time) *http.Cookie {
+	return MakeCookie(req, name, value, opts.CookiePath, opts.CookieDomain, opts.CookieHTTPOnly, opts.CookieSecure, expiration, now)
+}
--- a/pkg/sessions/cookie/session_store.go
+++ b/pkg/sessions/cookie/session_store.go
@ -27,36 +27,33 @@ var _ sessions.SessionStore = &SessionStore{}
 // SessionStore is an implementation of the sessions.SessionStore
 // interface that stores sessions in client side cookies
 type SessionStore struct {
+	CookieOptions *options.CookieOptions
 	CookieCipher  *cookie.Cipher
-	CookieDomain   string
-	CookieExpire   time.Duration
-	CookieHTTPOnly bool
-	CookieName     string
-	CookiePath     string
-	CookieSecret   string
-	CookieSecure   bool
 }

 // Save takes a sessions.SessionState and stores the information from it
 // within Cookies set on the HTTP response writer
 func (s *SessionStore) Save(rw http.ResponseWriter, req *http.Request, ss *sessions.SessionState) error {
+	if ss.CreatedAt.IsZero() {
+		ss.CreatedAt = time.Now()
+	}
 	value, err := utils.CookieForSession(ss, s.CookieCipher)
 	if err != nil {
 		return err
 	}
-	s.setSessionCookie(rw, req, value)
+	s.setSessionCookie(rw, req, value, ss.CreatedAt)
 	return nil
 }

 // Load reads sessions.SessionState information from Cookies within the
 // HTTP request object
 func (s *SessionStore) Load(req *http.Request) (*sessions.SessionState, error) {
-	c, err := loadCookie(req, s.CookieName)
+	c, err := loadCookie(req, s.CookieOptions.CookieName)
 	if err != nil {
 		// always http.ErrNoCookie
-		return nil, fmt.Errorf("Cookie %q not present", s.CookieName)
+		return nil, fmt.Errorf("Cookie %q not present", s.CookieOptions.CookieName)
 	}
-	val, _, ok := cookie.Validate(c, s.CookieSecret, s.CookieExpire)
+	val, _, ok := cookie.Validate(c, s.CookieOptions.CookieSecret, s.CookieOptions.CookieExpire)
 	if !ok {
 		return nil, errors.New("Cookie Signature not valid")
 	}
@ -74,11 +71,11 @@ func (s *SessionStore) Clear(rw http.ResponseWriter, req *http.Request) error {
 	var cookies []*http.Cookie

 	// matches CookieName, CookieName_<number>
-	var cookieNameRegex = regexp.MustCompile(fmt.Sprintf("^%s(_\\d+)?$", s.CookieName))
+	var cookieNameRegex = regexp.MustCompile(fmt.Sprintf("^%s(_\\d+)?$", s.CookieOptions.CookieName))

 	for _, c := range req.Cookies() {
 		if cookieNameRegex.MatchString(c.Name) {
-			clearCookie := s.makeCookie(req, c.Name, "", time.Hour*-1)
+			clearCookie := s.makeCookie(req, c.Name, "", time.Hour*-1, time.Now())

 			http.SetCookie(rw, clearCookie)
 			cookies = append(cookies, clearCookie)
@ -89,60 +86,42 @@ func (s *SessionStore) Clear(rw http.ResponseWriter, req *http.Request) error {
 }

 // setSessionCookie adds the user's session cookie to the response
-func (s *SessionStore) setSessionCookie(rw http.ResponseWriter, req *http.Request, val string) {
-	for _, c := range s.makeSessionCookie(req, val, s.CookieExpire, time.Now()) {
+func (s *SessionStore) setSessionCookie(rw http.ResponseWriter, req *http.Request, val string, created time.Time) {
+	for _, c := range s.makeSessionCookie(req, val, created) {
 		http.SetCookie(rw, c)
 	}
 }

 // makeSessionCookie creates an http.Cookie containing the authenticated user's
 // authentication details
-func (s *SessionStore) makeSessionCookie(req *http.Request, value string, expiration time.Duration, now time.Time) []*http.Cookie {
+func (s *SessionStore) makeSessionCookie(req *http.Request, value string, now time.Time) []*http.Cookie {
 	if value != "" {
-		value = cookie.SignedValue(s.CookieSecret, s.CookieName, value, now)
+		value = cookie.SignedValue(s.CookieOptions.CookieSecret, s.CookieOptions.CookieName, value, now)
 	}
-	c := s.makeCookie(req, s.CookieName, value, expiration)
-	if len(c.Value) > 4096-len(s.CookieName) {
+	c := s.makeCookie(req, s.CookieOptions.CookieName, value, s.CookieOptions.CookieExpire, now)
+	if len(c.Value) > 4096-len(s.CookieOptions.CookieName) {
 		return splitCookie(c)
 	}
 	return []*http.Cookie{c}
 }

-func (s *SessionStore) makeCookie(req *http.Request, name string, value string, expiration time.Duration) *http.Cookie {
-	return cookies.MakeCookie(
+func (s *SessionStore) makeCookie(req *http.Request, name string, value string, expiration time.Duration, now time.Time) *http.Cookie {
+	return cookies.MakeCookieFromOptions(
 		req,
 		name,
 		value,
-		s.CookiePath,
-		s.CookieDomain,
-		s.CookieHTTPOnly,
-		s.CookieSecure,
+		s.CookieOptions,
 		expiration,
-		time.Now(),
+		now,
 	)
 }

 // NewCookieSessionStore initialises a new instance of the SessionStore from
 // the configuration given
-func NewCookieSessionStore(opts options.CookieStoreOptions, cookieOpts *options.CookieOptions) (sessions.SessionStore, error) {
-	var cipher *cookie.Cipher
-	if len(cookieOpts.CookieSecret) > 0 {
-		var err error
-		cipher, err = cookie.NewCipher(utils.SecretBytes(cookieOpts.CookieSecret))
-		if err != nil {
-			return nil, fmt.Errorf("unable to create cipher: %v", err)
-		}
-	}
-
+func NewCookieSessionStore(opts *options.SessionOptions, cookieOpts *options.CookieOptions) (sessions.SessionStore, error) {
 	return &SessionStore{
-		CookieCipher:   cipher,
-		CookieDomain:   cookieOpts.CookieDomain,
-		CookieExpire:   cookieOpts.CookieExpire,
-		CookieHTTPOnly: cookieOpts.CookieHTTPOnly,
-		CookieName:     cookieOpts.CookieName,
-		CookiePath:     cookieOpts.CookiePath,
-		CookieSecret:   cookieOpts.CookieSecret,
-		CookieSecure:   cookieOpts.CookieSecure,
+		CookieCipher:  opts.Cipher,
+		CookieOptions: cookieOpts,
 	}, nil
 }

--- a/pkg/sessions/session_store.go
+++ b/pkg/sessions/session_store.go
@ -12,7 +12,7 @@ import (
 func NewSessionStore(opts *options.SessionOptions, cookieOpts *options.CookieOptions) (sessions.SessionStore, error) {
 	switch opts.Type {
 	case options.CookieSessionStoreType:
-		return cookie.NewCookieSessionStore(opts.CookieStoreOptions, cookieOpts)
+		return cookie.NewCookieSessionStore(opts, cookieOpts)
 	default:
 		return nil, fmt.Errorf("unknown session store type '%s'", opts.Type)
 	}
--- a/pkg/sessions/session_store_test.go
+++ b/pkg/sessions/session_store_test.go
@ -5,16 +5,20 @@ import (
 	"encoding/base64"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
+	"strings"
 	"testing"
 	"time"

 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
+	"github.com/pusher/oauth2_proxy/cookie"
 	"github.com/pusher/oauth2_proxy/pkg/apis/options"
 	sessionsapi "github.com/pusher/oauth2_proxy/pkg/apis/sessions"
 	"github.com/pusher/oauth2_proxy/pkg/cookies"
 	"github.com/pusher/oauth2_proxy/pkg/sessions"
-	"github.com/pusher/oauth2_proxy/pkg/sessions/cookie"
+	sessionscookie "github.com/pusher/oauth2_proxy/pkg/sessions/cookie"
+	"github.com/pusher/oauth2_proxy/pkg/sessions/utils"
 )

 func TestSessionStore(t *testing.T) {
@ -72,6 +76,16 @@ var _ = Describe("NewSessionStore", func() {
 				}
 			})

+			It("have a signature timestamp matching session.CreatedAt", func() {
+				for _, cookie := range cookies {
+					if cookie.Value != "" {
+						parts := strings.Split(cookie.Value, "|")
+						Expect(parts).To(HaveLen(3))
+						Expect(parts[1]).To(Equal(strconv.Itoa(int(session.CreatedAt.Unix()))))
+					}
+				}
+			})
+
 		})
 	}

@ -86,6 +100,10 @@ var _ = Describe("NewSessionStore", func() {
 				Expect(response.Header().Get("set-cookie")).ToNot(BeEmpty())
 			})

+			It("Ensures the session CreatedAt is not zero", func() {
+				Expect(session.CreatedAt.IsZero()).To(BeFalse())
+			})
+
 			CheckCookieOptions()
 		})

@ -138,12 +156,15 @@ var _ = Describe("NewSessionStore", func() {

 					// Can't compare time.Time using Equal() so remove ExpiresOn from sessions
 					l := *loadedSession
+					l.CreatedAt = time.Time{}
 					l.ExpiresOn = time.Time{}
 					s := *session
+					s.CreatedAt = time.Time{}
 					s.ExpiresOn = time.Time{}
 					Expect(l).To(Equal(s))

 					// Compare time.Time separately
+					Expect(loadedSession.CreatedAt.Equal(session.CreatedAt)).To(BeTrue())
 					Expect(loadedSession.ExpiresOn.Equal(session.ExpiresOn)).To(BeTrue())
 				}
 			})
@ -181,12 +202,16 @@ var _ = Describe("NewSessionStore", func() {
 			SessionStoreInterfaceTests()
 		})

-		Context("with a cookie-secret set", func() {
+		Context("with a cipher", func() {
 			BeforeEach(func() {
 				secret := make([]byte, 32)
 				_, err := rand.Read(secret)
 				Expect(err).ToNot(HaveOccurred())
 				cookieOpts.CookieSecret = base64.URLEncoding.EncodeToString(secret)
+				cipher, err := cookie.NewCipher(utils.SecretBytes(cookieOpts.CookieSecret))
+				Expect(err).ToNot(HaveOccurred())
+				Expect(cipher).ToNot(BeNil())
+				opts.Cipher = cipher

 				ss, err = sessions.NewSessionStore(opts, cookieOpts)
 				Expect(err).ToNot(HaveOccurred())
@ -231,7 +256,7 @@ var _ = Describe("NewSessionStore", func() {
 		It("creates a cookie.SessionStore", func() {
 			ss, err := sessions.NewSessionStore(opts, cookieOpts)
 			Expect(err).NotTo(HaveOccurred())
-			Expect(ss).To(BeAssignableToTypeOf(&cookie.SessionStore{}))
+			Expect(ss).To(BeAssignableToTypeOf(&sessionscookie.SessionStore{}))
 		})

 		Context("the cookie.SessionStore", func() {
--- a/providers/google.go
+++ b/providers/google.go
@ -149,6 +149,7 @@ func (p *GoogleProvider) Redeem(redirectURL, code string) (s *sessions.SessionSt
 	s = &sessions.SessionState{
 		AccessToken:  jsonResponse.AccessToken,
 		IDToken:      jsonResponse.IDToken,
+		CreatedAt:    time.Now(),
 		ExpiresOn:    time.Now().Add(time.Duration(jsonResponse.ExpiresIn) * time.Second).Truncate(time.Second),
 		RefreshToken: jsonResponse.RefreshToken,
 		Email:        c.Email,
--- a/providers/logingov.go
+++ b/providers/logingov.go
@ -252,6 +252,7 @@ func (p *LoginGovProvider) Redeem(redirectURL, code string) (s *sessions.Session
 	s = &sessions.SessionState{
 		AccessToken: jsonResponse.AccessToken,
 		IDToken:     jsonResponse.IDToken,
+		CreatedAt:   time.Now(),
 		ExpiresOn:   time.Now().Add(time.Duration(jsonResponse.ExpiresIn) * time.Second).Truncate(time.Second),
 		Email:       email,
 	}
--- a/providers/oidc.go
+++ b/providers/oidc.go
@ -87,6 +87,7 @@ func (p *OIDCProvider) redeemRefreshToken(s *sessions.SessionState) (err error)
 	s.AccessToken = newSession.AccessToken
 	s.IDToken = newSession.IDToken
 	s.RefreshToken = newSession.RefreshToken
+	s.CreatedAt = newSession.CreatedAt
 	s.ExpiresOn = newSession.ExpiresOn
 	s.Email = newSession.Email
 	return
@ -126,6 +127,7 @@ func (p *OIDCProvider) createSessionState(ctx context.Context, token *oauth2.Tok
 		AccessToken:  token.AccessToken,
 		IDToken:      rawIDToken,
 		RefreshToken: token.RefreshToken,
+		CreatedAt:    time.Now(),
 		ExpiresOn:    token.Expiry,
 		Email:        claims.Email,
 		User:         claims.Subject,
--- a/providers/provider_default.go
+++ b/providers/provider_default.go
@ -8,6 +8,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/url"
+	"time"

 	"github.com/pusher/oauth2_proxy/cookie"
 	"github.com/pusher/oauth2_proxy/pkg/apis/sessions"
@ -72,7 +73,7 @@ func (p *ProviderData) Redeem(redirectURL, code string) (s *sessions.SessionStat
 		return
 	}
 	if a := v.Get("access_token"); a != "" {
-		s = &sessions.SessionState{AccessToken: a}
+		s = &sessions.SessionState{AccessToken: a, CreatedAt: time.Now()}
 	} else {
 		err = fmt.Errorf("no access token found %s", body)
 	}